Fluid clutch or transmission



April 2, 1940. G. w. owENs FLUID CLUTCH 0R TRANSMISSION Filed lay 13, 1939 2 Sheets-Sheet 1 April 2 1940 l G. w. owl-:Ns 2,195,901

FLUID CLUTH 0R TRANSMISSION l Filed lay 15, 1939 2 Sheets-Sheet 2 ...Fg j.

J4 ATTORNEYS.

Patented Apr. 2, 1940 UNITED. STATES PATENT OFFICE.

16 Claims.

cerned with clutches and transmissions employing a liquid, such as oil or the like, to connect a drive and a driven shaft at a plurality of relative andcontrollable speeds. l

Heretofore various types of fluid and liquid clutches and transmissions have been suggested and employed. One well known type, called the hydro-static type, has the drive shaft connected to a lpump from which conduits convey the fluid to an adjacent or a remote fluid motor which is connected to the driven shaft. By varying the amount of uid pumped by the fluid pump the relative speeds between the drive and driven shafts can be varied. While this type of fluid transmission is quite flexible and'possesses the advantage of allowing the driven shaft to beremotely positioned and at any angle to the drive shaft, the system as a whole is expensive and space-consuming.

-Another type of fluid transmission or clutch, called'V the hydro-kinetic type, necessitates that the drive and driven shafts be in alignment. In this type of fluid clutch or transmission an impeller wheel similar to an impeller wheel on a steam turbine is connected to or associated with the drive shaft. Fluid thrown centrifugally by the impeller wheel associated with the drive shaft strikes an impeller wheel connected to or associated with the driven shaft whereby the driven shaft is rotated. The force and amount of liquid thrown determines the relative speed of the driven shaft with that of the drive shaft. This type of transmission has a number of disadvantages which'which include a time interval or buildup to effect an initial coupling action, and

the inability to establish a one-to-one ratio between the drive and driven shafts..

A third type of fluid clutch or transmission employs a standard vane type of fluid pump with a valve controlling the flow of fluid through the outlet port of the pump. Either the drive or driven shaft is connected to the rotor of the pump and the other shaft is connected to the casing of the pump.'A The degree of opening of the vvalve controls the flow of fluid through the pump and the degree with which the drivesliaft is allowed toturn faster.`than the driven shaft. An oil reservoir associated with the casing of the pump receives the oil from the valve outlet port of the pump and supplies oil to the inlet port. This type of transmissionl is perhaps the simplest of the several generic typesL mentioned but. has

. ysiderahle amount of heat is generated by the always beenv open to the objection that a con# vIt is the general object' of 'my invention of an improved liquid transmission including a of a fluid or liquid clutch or transmission having -avoid and overcome the foregoing and other difflculties attending the manufacture, sale, and use vof fluid clutches and transmissions bythe provision of an improved fluid clutch and transmission of relatively small size for any given horsepower so' that it occupies a minimum amount of space, which is inexpensive to manufacture, but rugged and long-lived, which can be readily adjusted to give the desired ratio between a drive and a driven shaft almost instantaneously; which does not require the use of a motor and a pump, which does not include a valve, and which will operate continuously to give a fixed ratio drive over long periods an without the evolution of harmful heat.

Another and more specific object of my invention is the provision of a lfluid transmission in which the operation of the transmission is controlled by controlling the fluid intake rather than by controlling the fluid output of a fluid Pump Another object of my invention is the provision of a fluid clutch or transmission in which the Y relative speed between a drive and afdriven shaft power is effected.

Another object of my invention is the provision a new and useful arrangement of parts and specifically including means for absorbing or dampening out a sudden load on the driven or even the drive shaft.

For a better understanding of my invention reference should be had to the accompanying drawings, in which Fig. 1 is a longitudinal vertical and diametric section through a uid transmission embodying the principles of my invention; Figs. 2 and 3 are transverse cross sectional views taken respectively on lines II-II and III-III of Fig. 1; Fig. 4 is a perspectivev View of the rotor body forming a part of the apparatus; Fig. 5 is a perspective view of the blades or vanasV associated with the rotor body of Fig. 4; and Fig. 6 is a longitudinal vertical sectional View of one of the cushioning means associated with the apparatus.

yIt will be understood that fluid transmissions 55 constructed in accordance with my invention can be made in'substantially any size and adapted to handlev substantially any required horsepower.

fHowever, my invention particularly adapts itself to. operations in conjunction with a constant f speed electric motor. An induction motor having a constant speed is one of the best. prime movers known s o far as eiciency is concerned, and accordingly, I have illustrated my invention in conjunction with an induction or other electric motor marked M. It will be recognized that when my improved transmission is employed in conjunction with a constant speed electric motor or other primemover that the advantages of inexpensiveness and high efficiency of the electric motor are coupled with the flexibility of my transmission to give any desired speed to a driven shaft. Furthermore, the losses due to friction and the like are relatively small in my transmission so that the resulting unit retains substantially the e'iciency of the prime mover and possesses in addition the said variable speed flexibility.

Accordingly, in the accompanying drawings an electric motor M or other prime mover is coupled by means I0 of any desired type to a drive shaft I2 forming a part of my improved transmission apparatus. The drive shaft I2 is rotatably carried in a combined radial and thrust bearing |4 mounted in an end plate |6. The end plate I6 is connected by a housing I8 to an opposite end plate 20 which carries a combined radial and thrust bearing 22 which rotatably receives a driven shaft 24 which is coupled by any suitable means 26 to the shaft 28 of the apparatus to be driven. The end plates I6 and 20 and thus the entire housing of the apparatus are usually secured as by bolts or cap screws 30 to a frame or other foundation.

The drive shaft I2 carries a rotor head indicated as a whole by the numeral 32. To obtain flexibility between the rotor head 32 and the drive shaft I2 I generally connect these parts by a spline 34. The rotor head 32 includes a cylindrical body 36, shown individually in Fig. 4, which is formed with four slots 38 and 40 on each end which extend radially at each of the quadrants of a circle. The slots 38 at one end of the cylindrical body 36 are separated from the slots 40 at the other end of the body by a partition or wall 42 which is usually formed integral with the body. The cylindrical rotor body 36 is secured as by countersunk screws 46 to a round plate 48 formed with a hub portion 50 which receives the end of the drive shaft I2. A round plate 52 is secured as by countersunk screws 54 to the other end of the cylindrical rotor body 36. The plate 52 is provided with a stud 56 which is received in a combined radial and thrust bearing 58 carried by the casing of the rotary pump and hereinafter described.

The radial slots 40 formed at one end of the cylindrical rotor member 36 slidably receive blades or vanes 60. As clearly shown in Figs. 1 and 2, the blades 60 are secured together in pairs by pins 62 which are usually slidably received in openings drilled in the base of the blades.

Springs could be used to force the blades 60 out into contact with the casing of the fluid pump, as will be understood by those skilled in the art. However, using the pins 62 rather than springs simplifies the construction of the pump and the desired sealing of the blades 60 against the surrounding casing of the pump is achieved by the centrifugal force urging the blades outwardly when the pump is revolved at considerable speed by the motor M. In a like manner blades 64 are received by the slots 38 in the cylinl drical rotor member 36 and pins 66 are used to augntne blades in pairs..

course, that other means may Surrounding the blades 60 and 64 and thecylindrical rotor members 36 and plates 52 and 48 carried by the drive shaft I2 is the casing of the pump, indicated as a whole by the numeral 10. Although it will be understood that the casing 10 can be-formed in any known or desired manner, it is conveniently made in two transversely split parts marked 12 and 14 in the drawings. The part 12 of the casing 10 is formed with a reduced end portion 16 which is carried in a combined radial and thrust bearing 18 mounted in a circular web formed on the end plate I6 ofthe housing. A suitable sealing means 82 is usually provided between the reduced end portion 16 of the casing part 12 and the drive shaft l2. This sealing means may take any desired form as will be understood. The casing part 12 likewise Surrounds a combined radial and thrust bearing 84 which engages with the outer peripheryof the hub 50 associated with the drive shaft I2.

The casing part 12 is formed with a round `cylindrical chamber which is positioned eccentrically of the axis of the drive shaft I2 all in accordance with standard fluid pump practice and as hereinafter more particularly described.

Suffice it to say here that the blades 60 rotate in the eccentric chamber 90 formed in the part 12 of the casing 10.

'I'he part 14 of the casing 10 is formed with an eccentrically-positioned, round cylindrical chamber 9,2 which receives the rotor blades 64. Further, the part 14 of the casing 10 is provided with v an inwardly extending flange 94 to which is secured a ange 96 formed integral with or associated with the driven shaft 24. The flange 94 surrounds and bears upon the radial and thrust bearing 58 heretofore described as receiving the stud 56 associated with the rotor member 32.

The two parts 12 and 14 of the casing 10 may be secured together byV cap screws |00. A spacing washer |02 of the same longitudinal thickness as the partition wall 42 is clamped between the parts 12 and 14 of the casing by the cap screws |00. Each of the casing parts is formed with an outwardly and then longitudinally directed wall portion which portions are bolted together as at |04 to provide a sump or pressure chamber |06. The radiallyouter walls ofthe pressure chamber |06 may be provided with integral or associated cooling ribs |08 if desired.

Fluid may be placed in the pressure chamber |06 by removing a closure plug ||0. Also communicating with the inside of the pressure chamber |06 is a conduit |I2 which is connected to a passageway ||4 formed in the driven shaft 24. A suitably packed connector ring assembly, indicated as a whole by the numeral |I6, supplies fluid from a conduit ||8 to the passageway ||4 in the driven shaft 24. A master pressure cylinder ofY standard type having a screw-operated piston, and indicated as a whole by the numeral |20, is connected to the conduit IIB. 'I'he master pressure cylinder |20 is illustrated as having a hand wheel |22 for operating the piston of the pressure cylinder. It will be appreciated, of be employed to operate the pressure cylinder, as for example, a foot pedal or hand lever, to thereby control the pressure in the pressure chamber I06.

The numeral |26 indicates a pressure cushioning unit which is associated with the pressure chamber |06 so that any sudden changes of pressure inthe chamber are cushioned or absorbed. As will be evident from Fig. 6, the cushioning unit includes a cylinder |28v and a double piston compress it and at the same time air is vented,

out of the opening |34 from behind the piston |30. Fluid under pressure froml the pressure chamber, of course, engages with the side of the II and III of Fig. 1.

piston remotefrom the spring |32/'at all times inasmuch as the fluid under pressure from the chamber flows through opening |36.

An important part of my invention is the provision of va controlled intake for the fluid pump or pumps above described, together with a control of the flow of fluid from the outlet port or ports 'by pressure rather than by valve means. For a better understanding of this phase of my invention reierenceshould be had to Figs. 2 and 3 which are sections taken respectively on lines Having reference first to Fig. 2, the cylindrical rotor member 36 received in the ecc'entrically positioned cylindrical chamber 92 has a point of tangency at T with the inner surface of the chamber. 'Ihus in the rotation of the member 36 in the direction shown by the arrow the blades 64 act in accordance with the standard fluid pump to provide what might be termed an intake, vacuum or suction stroke from the point T approximately to a point 180 degrees distant therefrom. In the remaining l 2, at some part of the initialpressure or discharge stroke of each blade 64 and I have found one convenient pointfor such an inlet port to be approximately 115 degrees ahead of the point of tangency T. 'I'he inlet port |40 is of a relatively small bore whose diameter may be important to the correct functioning of my apparatus. The

exact ,diameter of the port |40 may be found in tioned approximately 221/2 degrees in front practice by atrial and error method, but as one example of a typical port, I have found that in an apparatus in which the length of each blade 64 is approximatelyone inch and the cylindrical rotor member 36 is approximately 1% inches in diameter and the internal diameter of the cylindrical chamber 92 is lg inches, the diameter of the inlet port I 40 may be approximately gli inch or slightly greater. The outlet port, marked in Fig. 2 by the numeral |42, is positioned substantially as usual, namely, about 221/2 degrees in advance of the point of tangency T. The diameter of the outlet port may be similar to that of' the inlet port or perhaps slightly greater.

In a similar manner the fluid pump formed by the blades 60 and operating in the cylindrical, cccentrically-positioned chamber is formed with an inlet port |46 positioned about 115 degrees ahead of the point of tangency T between `the cylindrical rotor member 36 and the eccentric chamber 90. The outlet port |48 is posiof the point of tangency T.

As particularly illustrated in Fig. 2 of the drawings, the point of tangency T of the eccentric cylinder 02` is approximately 135 degrees ahead of the position of the point of tangency T' oi the eccentric cylinder 90. This relation of the points of tangency insures a smoother operation of the apparatus as Will be explained in detail hereinafter. Suflce it to say here that when one of the blades 64 of one pump has just actively completed a pressure stroke, namely, the blade is just moving by the outlet port |42, one of the' 'blades 60 is actively beginning or is in the middle of an active pressure stroke to discharge fluid out of the outlet port I 48. Similarly, as soon as one of the blades 60 has passed the outlet port |48, the next blade 64 has already begun an active pressure stroke. It should be noted here that by increasing the number of blades in the rotor member 36 any need for a pair of pressure chambers or pumps would be eliminated. For

example, on larger sized forms of my apparatus a single rotor member can carry anywhere up to nine or more blades and eiect the smoothest type of pressure discharge operation. However, I have found that when machine design or purposes of convenience result in a given rotor carrying only two to six or so blades that my apparatus operates more smoothly when a pair of pumps or pressure chambers are positioned end to end in axial alignment, in the manner shown in Figs. 1 to 3 of the drawings, and these pumps or eccentric chambers are offset circumferentially from each other as by making the points of tangency T and T at an angle of approximately degrees with each other. Naturally,'I may employ more than two fluid pumps orpressure chambers in end to end relation and offset the points of tangency in an appropriate manner so or pressure chamber come into their pressure stroke in turn to give a very smooth action.

In the operation of my improved fluid clutch or transmission the pressure chamber |06 is filled that, the individual blades carried in each pump with oil or other suitable fluid or liquid and this may be achieved by the combined operation oi the master cylinder |20 and the plug ||0 so that all air is exhausted from the system. Let it be assumed that the motor M is energized and connected to the drive shaft I2 for rotating it and the rotor member 36 at a constanty speed, and that the hand wheel` |22 is adjusted so that the master cylinder |20 produces a negative pressure on the oil in chamber |06 substantially equal to the negative pressure produced by chamber 92. Now since the operation of the blade 64 in the chamber 92 is exactly similar to the operation of the blades 60 in the chamber 90, only the operation of one set of blades will be considered. With the rotor member 36 turning the blades 64 at a constant speed relative to the casing |0and the chamber 92, then, upon the movement of each blade 64 from the tangent T to a point approximately degrees opposite, a vacuum will be `created in the chamber following each blade.

However, no oil can get into this particular chamber behind each blade from the pressure chamber |06 because there is no inlet port connecting these two chambers. But after the blade has traveled further around to and has just passed the inlet port |40 there will be a tendency for fluid in the pressure chamber |06 to flow through the inlet port |40 into the evacuated chamber behind the blade which has just passed the inlet port. Ihe reason for this tendency of the fluid to ow through inlet port |40 is the pressure head of the oil in chamber |06. However, except for this pressure head the pressure on the fluid in the pressure chamber |36 is the same as that in the chamber 92. and inasmuch 'as inlet port |40 is very small and the rotor is turning at a relatively high speed which provides only a very small time interval for the space between any two bades in chamber 92 to have communication with port |40, substantially no fluid will flow into the chamber behind the bladev 64 which has just passed the inlet port |40. Whatever slight amounts of oil happen to enter chamber 92 through port |40 will be expelled from the chamber through port |42 by the blades 64 without providing any driving torque, due to the relatively low pressure on the fluid in chamber |06 at the exit end of outlet port |42. `Accordingly, the rotor member 36 turns freely in the chamber 92 and no motion is given to the casing '|0 or to the driven shaft 24. When the pressure in the chamber |06 is the same as that in the chamber 92 the pressure may be below atmospheric. If this is the case the pistons |30 are moved completely to the left-hand ends of the cylinders |28 and the extra fluid put into the system is compensated for by the master cylinder |20. Usually the master cylinder adjustment to idling position moves the pistons |30 as described.

Now, assuming that the operator desires to operably connect the driven shaft 24 to the drive shaft I2, the hand wheel |22 on pressure cylinder |20 is turned to place a given pressure on the oil in the pressure chamber |06. Now, after a given blade 64 passes the inlet port |40, oil under pressure is forced into the evacuated chamber behind the blade. The continued rotation of the member 36 prevents the chamber from being completely lled before the next blade 64 passes the inlet port |40 and cuts off the ow of oil into the chamber. With a relatively light pressure in the pressure chamber |06 as effected by the pressure of the master cylinder |20, the chamber behind each blade will only be filled say ten per cent of its volume. Thus in the pressure or discharge stroke of each blade 64 only a relatively small amount of oil has to be passed through the outlet port |42. Inasmuch as this forcing out of the oil through the outlet port |42 can not be instantaneous the rotor member 36 will pick up the casing 10 connected to the driven shaft 24 and turn the casing ata speed which Will havea direct and constant ratio to the speed of the drive shaft |2 so long as the pressure of the master cylinder and the pressure cylinder |06 remains constant. Ordinarily the speed of the driven shaft 24 will be a comparatively small fraction, such as 116 of the speed of the drive shaft. g

Now, if the pressure in the`master cylinder .|20 is increased by further tightening the hand wheel |22, a greater differential will exist between the pressure in the evacuated chamber behind the blade 60 just after it passes the inlet port |40 and the pressure in the pressure chamber |06. Thus, a greater amount of oil will be forced into each evacuated chamber in turn. This greater amount of oil is discharged more slowly from the outlet port 42 by each blade 64 and the speed of the driven shaft 24 is correspondingly increased. Furthermore, the greater amount of oil forced into the evacuated chamber with greater pressure is due also to the fact thatV the relative speed between the rotor member 36 and the casing l0 is, not so great and a longer time interval exists during which the chamber behind, each blade is in communication with the inlet port |40. Thus, with a higher pressure the speed of the driven shaft with respect to that of the drive shaft may come up to approximately half that of the drive shaft. A further increase in pressure in the master cylinder |20 still further increases the speed of the driven shaft 24. In this manner any one of substantially any desired relative speeds between the drive shaft and the driven shaft can be obtained and once this desired speed is obtained it will remain substantially constant over long periods of operation.

If it is desired to obtain a one to one drive betweenthe drive shaft and driven shaft the pressure in the master cylinder |20 is increased, as just described, up to a point where the driven shaft is rotating almost at the speed of the drive shaft. In other words, sufficient oil is being introduced through the inlet port |40 during the pressure intake so that the space behind each blade 64 is substantially lled and this entire yamount of fluid must be discharged through the outlet chamber |42. 'I'he discharge of the fluid from the outlet port takes place at a much slower speed than does the intake of the fluid for the reason that the pressure differential between the opposite ends of the outlet port is much less than the pressure differential between the opposite ends of the inlet port 40. Now, when the discharge of fluid from the outlet port |42 is progressing very slowly, if the pressure on the master cylinder |20 is particularly increased, then the point is reached where the pressure at the outlet end of the outlet port is greater than or equal to the pressure at the inlet end of the outlet port. Hence no oil is discharged out of the outlet port and the casing '|0 and the driven shaft 24 are rotated at the same speed as the rotor.member 36 and drive shaft I2. Any possible leakage of oil past the tangent point T or elsewhere in the system either with the one to one drive or at any other relative speeds is compensated for without change of relative speed by the cushioning or displacement cylinders |26 as will be recognized by those skilled in the art.

I have found that speed variations of the drive shaft 24 substantially from zero up to almost the speed of the drive shaft can be achieved by relatively small pressure changes in the master cylinder |20. Further the locking of the rotor member 36 with the casing 10 to effect a one to one drive between the drive shaft and the driven shaft can be readily effected by adding pressure in an additional amount to the pressure cylinder which is capable of relatively high pressure if desired.

As heretofore explained, by placing a plurality of pumps or pressure cylinders in end to end alignment but in circumerentially offset relation any tendency to jerk or vibrate in my improved transmission is substantially eliminated even though a relatively small number of blades f are used in each pump.

If during the operation of a machine from an electric motor having my transmission connecting the motor to a machine, a sudden overload on the machine occurs, the cushioning cylinders |28 absorb the increase in pressure or the necessary fiuid displacement and the result is a cushioning or shock absorbing action between the motor and the machine.

As indicated in Fig. 1, I may secure a plurality of fan blades |60 to the outer periphery of one end of the casing 10 and provide the end plates |6 and 20 with openings |62 so that the rotaltion of the casing 10 causes a circulation of cooling air through the housing.

From the foregoing it will be recognized that the objects of my `invention have been 4achieved by the provision of an improved uid clutch or transmission which departs from and overcomes I many of the objectionable features of prior known types of transmissions. I am able to drive either constant torque or varying torque machines or apparatus with my improved apparatus. I have materially reduced the expense and space requirements of certain known vforms of fluid transmissions and have avoided the difficulties associated with the valve type of uid transmission. My apparatus is inexpensive to build, easily installed and operated and functions over long periods substantially without ati tention or repair. It possesses the ability to transmit power at widely varying ranges of speed and high efficiency under instant and accurate control. its ranges of use are Wideand varied but will be grasped by those skilled in the art.

VVhile'I have particularly illustrated and described my advance in the art, all in accordance with the patent statutes, it should be particu.- larly understood that my invention is not to be limited thereto or thereby but that it is defined in the appended claims.

I claim:

l. A fluid transmission comprising a rotary pump including a casing and a rotor adapted to provide suction and pressure strokes with respect to the casing, a driven shaft secured to the casing of the pump, a drive shaft secured to the rotor of the pump, an inlet port on the pump casing positioned beyond the suction stroke of the pump, an outlet port on the pump casing positioned adjacent the end of the pressure stroke of the pump, a'pressure chamber connected to the inlet and outlet ports of the pump, and means to apply any desired pressure on the fluid in the chamber.

2. A fluid transmission comprising a rotary pump including a casing and a rotor adapted to provide suction and pressure strokes with respect to the casing, a driven shaft secured to either the casing or the rotor of the pump, a drive shaft secured to the remaining part of the pump, an inlet port on the pump casing positioned beyond the suction stroke of the pump, an outlet port on the pump casing positioned adjacent the end of the pressure stroke of the pump, a pressure chamber connected to the inlet and outlet ports of the pump, and means to apply any desired pressure on the uid in the chamber.

3". A uid transmission comprising a plurality of rotary pumps aligned axially but offset circumferentially, each pump including a casing and a rotor adapted to provide suction and pressure strokes with respect to the casing, a driven shaft secured to the casings of the pumps, a drive shaft secured to the rotors of the pumps, inlet ports on the casings of the pumps positioned beyond the suction strokes of the pumps, outlet ports on the casings of the pumps positioned adjacent the ends of the pressure strokes of the pumps, a pressure chamber connected to the inlet and out- 4let ports of the pumps, and means to apply any gree of pressure to the chamber so as to control both the supply of uid in through the inlet port and out of the outlet port.

5. A uid transmissioncomprising a rotary pump including a casing and a rotor adapted to provide suction and pressure strokes with respect to the casing, a drive shaft connected to thefrotor of the pump, a driven shaft connected to the casing of the pump, said pump having inlet and outlet ports, positioned respectively near the beginning and end of the pressure stroke of the pump, a chamber connected to the inlet and outlet ports, and means for supplying fluid under any desired pressure to the chamber.

6. A fluid transmission comprising a rotary pump including a casing and a rotor adapted to provide suction and pressure strokes with respect to the casing, a drive shaft connected to the rotor of the pump, a driven shaft connected to the casing of the pump, said pump having inlet and outlet ports, positioned respectively near the beginning and end of the pressure stroke of the pump, a chamber connected to the inlet and outlet ports, and means for supplying fluid under any desired pressure to the chamber, and means associated with the chamber for absorbing pressure shocks in the system. j

'7. A fluid transmission comprising a fixed housing, a rotary pump rotatably journaled in the housing and including a casing and a rotor adapted to provide-suction and pressure strokes with respect to the casing, a drive shaft journaled in the housing and connected to the rotor of the pump, a driven shaft journaled in the housing and connected to the casing of the pump, said pump having inlet and outlet ports, a pressure chamberrotatable with the pump casing for supplying uid to the inlet port and for receiving the fluid from the outlet port, and a master pressure cylinder mounted outside the housing for supplying uidiunder pressure to the pressure chamber.

8. A uid transmission comprising a plurality of aligned but out of phase rotary pumps, each pump including a casing and a rotor adapted to provide suction Vand pressure strokes with respect to the casing, a drive shaft connected to the tied-together rotors of the pumps, a driven shaft connected to the connected casings of the pumps, said pumps vhaving inlet and outlet ports, a pressure chamber for supplying fluid to the inlet port and for receiving the uid from the outlet port, and a master cylinder for controlling the pressure in the pressure chamber.

9. A uid transmission comprising a plurality of aligned but out of phase rotary fluid pumps, each pump including a casingand a rotor adapted to provide suction and pressure strokes with respect to the casing, a drive shaft connected to the tied-together rotors of the uid pumps, a driven shaft connected to the connected casings 4of the fluid pumps, said pumps having inlet and outlet ports, a pressure chamber for supplying fluid to the inlet port and for receiving the uid from the outlet port, a master cylinder for controlling the pressure in the lpressure chamber,

vand means associated with the pressure chamber for vabsorbing sudden pressure shocks to the 4 fluid system.

10. A uid transmission comprising a driven shaft, a cylindrical casing secured to the driven shaft, a pressure chamber surrounding the lgasling, a drive shaft, a rotor cylinder secured to the drive shaft and eccentrically positioned in the cylindrical casing, a plurality of radially-extending, axially directed blades slidably carried at y I circumferentially spaced points about the rotor cylinder, and means for supplying fluid under any desired pressure to the pressure chamber, said cylindrical casing having an exhaust port opening to the pressure chamber and having an inlet port opening to the pressure chamber and positioned to be open to the inside of the cylindrical casing only after the complete suction stroke of each blade carried by the rotor cylinder.

1l. A iiuid transmission comprising a driven shaft, a casing secured to the driven shaft and having an eccentrically-positioned cylindricaly opening therein, a pressure chamber surrounding the casing, a drive shaft in alignment with the driven shaft, a rotor cylinder secured to the drive shaft and received in the cylindrical opening in the casing so that the rotor cylinder and opening are tangent to each other at one point, a plurality of radially-extending, axially directed blades slidably carried at circumferentially spaced points about the rotor cylinder, and means for supplying fiuid under any desired pressure to the pressure chamber, said cylindrical casing having an exhaust port opening to the pressure chamber and having an inlet port opening to the pressure chamber and positioned to be open to the inside of the cylindrical casing only after the complete suction stroke of each blade carried by the rotor cylinder.

l2. A fluid transmission comprising a driven shaft, a casing secured to the driven shaft and having an eccentrically-positioned cylindrical opening therein, a pressure chamber surrounding the casing, a drive shaft in alignment with the driven shaft, a rotor cylinder secured to the drive shaft andreceived in the cylindrical .opening in the casing so that the rotor cylinder and opening are tangent to each other at one point, a plurality of radially-extending, axially-directed blades slidably carried at circumferentially spaced pointsabout the rotor cylinder, means for supplying fluid under any desired pressure to the pressure chamber, said cylindrical casing having an exhaust port opening to the pressure chamber andhaving an inlet port4 opening to the pressure chamber and positioned to be open to the inside of the cylindrical casing only after the complete suction stroke of each blade carried by the rotor cylinder, and means associated with the pressure chamber for cushioning sudden pressure shocks to the fluid system.

13. A fluid transmission comprising a stationary housing, a drive shaft, a combined radial and thrust bearing journalliig the drive shaft in the housing, a driven shaft, a combined radial and thrust bearing journalling the driven shaft in the other 4side of the housing and in alignment with the drive shaft, a casing secured 'to the driven shaft and having a reduced end portion surrounding the drive shaft, a combined radial and thrust bearing journalling the reduced end portion of the casing in the housing, a combined radial and thrust bearing associated with the reducedend portion offthe casing and journalling the drive shaft, said casing having an eccentrically-positioned cylindrical opening therein, a pump rotor received in the cylindrical opening and splined to the drive shaft, a stud on the end of the rotor remote from the drive shaft, a combined radial and thrust bearing carried by the casing and journalling the stud, a pressure chamber surrounding the casing, a master pressure cylinder, means connecting the master pressure cylinder to the pressure chamber, said casing having an outlet port fromthe discharge side of the fluid rotor to the pressure chamber and an K inlet port to the pressure chamber and positioned i between the end of the suction stroke and the middle of the pressure stroke, and a displacement cylinder associated with the pressure chamber.

14. A uid transmission comprising a stationary housing, a drive shaft, a bearing journalling the drive shaft in the housing, a driven shaft, a bearing journalling the driven shaft in the other side of the housing and in alignment with the drive shaft, a casing secured to the driven shaft and having a reduced end portion surrounding the drive shaft, a bearing journalling the reduced end portion of the casing in the housing, a bearing associated with the reduced end portion of the casing and journalling the drive shaft, said casing having an eccentrically-positioned cylindrical opening therein, a pump rotor received in the cylindrical opening and splined to the drive shaft, a stud on the end of the rotor remote from the drive shaft, a bearing carried by the casing and journalling the stud, a pressure chamber surrounding the casing, a master pressure cylinder, means connecting the master pressure cylinder to the pressure chamber, said casing having an outlet port from the discharge side of the rotor to the pressure chamber and an inlet port to the pressure chamber and positioned between the end of the suction stroke and the middle of the pressure stroke, and a displacement cylinder associated with the pressure chamber.

15. A fluid transmission comprising a stationary housing, a drive shaft, a bearing journalling -the drive shaft in the housing, a driven shaft,

a bearing 4journalling the driven shaft in the other side of the housing and in alignment with the drive shaft, a casing secured to the driven shaft and having a reduced end portion surrounding the drive shaft, a bearing journalling the reduced end portion of the casing in the housing, a bearing associated with the reduced end portion of the casing and journalling the drive shaft, said casing having an eccentrically-positioned cylindrical opening therein, a pump rotor received in the cylindrical opening and splined to the drive shaft, a stud on the end of the rotor remote from the drive shaft, a bearing carried by the casing and journalling the stud, a pressure chamber surrounding the casing, a master p`ressure cylinder, and means connecting the master pressure cylinder to the pressure chamber, said casing having an outlet port from the discharge side of the rotor to the pressure chamber and an inlet port to the pressure chamber and positioned between the end of the suction stroke and the middle of the pressure stroke.

16. A fluid transmission comprising a stationary housing, a drive shaft, a-bearing journalling the drive shaft in the housing, a driven shaft, a. bearing journalling the driven shaft in the other side of the housing and in alignment with the drive shaft, a casing secured to the driven shaft and having a reduced end portion surrounding the drive shaft, a bearing journalling the reduced end portion of the casing in the housing, a bearing associated with the reduced end portion of the casing and journalling the drive shaft, said casing having an eccentrically-positioned cylindrical opening therein, a rotary pump rotor received in the cylindrical opening and splined to the drive shaft, a stud on the end of the rotor remote from the drive shaft, a bearing carried by the casing and journalling the stud, and a pressure chamber surrounding the casing.

' GEORGE W. OWENS. 

